-—”On the other hand you can smell ammonia even in low concentrations and can get the heck out.”
My S.I.L. works for a biggie in the ammonia refrigeration business and I met a guy that had his hand on the door of the machine room as it BLEW UP!!
He was the contact person when the alarm went off!
The firemen were with him, no serious injuries.
In this area, large exhaust fans tied to sensors/alarms are required.
Ask your friend about R-290.
“Ask your friend about R-290.”
The Wikipedia information on it is within the Propane article.